The Sydney offices of independent MP Alex Greenwich have been graffitied with homophobic slurs.
Mr Greenwich said he has previously received "written threats, phone abuse, social media, but never anything like this".
NSW Police are investigating the incident and urge anyone with information to come forward.
Homophobic graffiti sprayed on the outside walls and windows of Sydney MP Alex Greenwich's office is under investigation by NSW Police.
Mr Greenwich told the ABC that the vandalism was unprecedented.
"I've got lots of written threats, phone abuse, social media, but never anything like this," he said.
Reports of the attack at the Oxford Street premises in the inner-east Sydney suburb of Surry Hills were received by police on Sunday at about 12pm.
"A crime scene has been established, and investigators are reviewing CCTV and conducting inquiries to identify the people involved," police said in a statement.
In a post on social media, Mr Greenwich said the incident was "deeply distressing" for both his staff and himself.
"No-one should face this kind of hatred in their workplace, especially on the 9th anniversary of Australia’s marriage equality YES vote," the post said.
"If the intention was to intimidate me, it has had the opposite effect. I’m more determined than ever to make Sydney and NSW safer, fairer and more equal for our community."